Transfers of Financial Assets - Summary of Carrying Amount of Financial Assets (Detail) - EUR (€) € in Millions	Dec. 31, 2022	[1]	Dec. 31, 2021
Available-for-sale financial assets [member] | Shares [member]
Disclosure of financial assets [line items]
Carrying amount of transferred assets	€ 0		€ 34
Carrying amount of associated liabilities	0		37
Available-for-sale financial assets [member] | Debt securities [member]
Disclosure of financial assets [line items]
Carrying amount of transferred assets	2,200		3,705
Carrying amount of associated liabilities	2,513		3,941
Financial assets at fair value through profit or loss [member] | Debt securities [member]
Disclosure of financial assets [line items]
Carrying amount of transferred assets	16		12
Carrying amount of associated liabilities	17		18
Financial assets at fair value through profit or loss [member] | Investment contracts for account of policyholders [member]
Disclosure of financial assets [line items]
Carrying amount of transferred assets	72		96
Carrying amount of associated liabilities	€ 0		€ 0

[1] 2022 excludes the assets and liabilities of the disposal group, which are separately disclosed in note 51 Discontinued operations.